Mouse slows down dramatically whenever starting recently updated Firefox

[dawog]

My Windows 7 updated today to v115.9.1esr (64-bit) today.  Afterwards, my trackball slows down dramatically whenever I start Firefox & it's window has the focus.  Started Firefox in Safe Mode & problem remains.  Tried a mouse instead of my Kensington trackball & it behaves the same way.  Rebooted PC... problem remains.  Whenever active window is not Firefox, mouse/trackball work fine.  My PC is Dell XPS 8900 running Windows 7 Professional w/Service Pack 1, 64-bit.

This wasn't an issue with Firefox v115.9.0esr (64-bit)

[dawog · Accepted solution]

As Roseanne Roseannadanna says... "Never mind."  I uninstalled & reinstalled my Kensington trackball software/drivers for the SECOND time, and this time both trackball (& mouse) appear to be working normally.  (I really feel like a turd for posting this bug, especially knowing the 99% of the time it's "user error")